Electric-circuit connector.



W. P.-MULLIGAN. ELECTRIC CIRCUIT CONNECTOR.

APPLICATION FILED JAN-19. I914.

1,1 58,708. Patented Nov. 2, 1915.

2 SHEETS-SHEET I.

W. P. MULLIGAN.

ELECTRIC CIRCUIT CONNECTOR.

APPLICATION FILED JAN. 19, i914.

1,158,708. v Patented Nov. 2, 1915.

2 SHEETS-SHEET 2.

STAS

WILLIAM PATRICK MULLIGAN, OF ST. PAUL, MINNESOTA, ASSIGNOR F ONE-HALF TO I ANDREW ROSS, OF ST. PAUL, MINNESOTA.

ELECTRIC-CIRCUIT CONNECTOR.

Specification of Letters Patent.

Patented Nov. 2, 1915.

Application filed January 19, 1914. Serial No. 812,914.

To all whom it may concern Be it known that I, WILLIAM PATRICK MULLIGAN, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and .useful Improvements in Electric-Circuit Connectors; and I do hereby declare the following to be a full, clear, and eXact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to electric circuit connectors, and it is especially adapted for use in connection with electric lighting systems of railway trains, wherein the electric lights are operated in connection with a series of conductors extending lengthwise of the train, three conductors being commonly employed. In such systems, to permit ready coupling and uncoupling of the cars, the conductors are provided, at the ends of the cars, with couplings or connecting devices, commonly known as connectors. There is alsoemployed, in such systems, means for connecting two of the conductors at the end of the train, for use in what is commonly known as the return-loop system.

My invention pertains particularly to this class of connectors and return-loop systems, and has for its object to improve the same in the several particulars hereinafter described and defined in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like views.

Referring to the drawings: Figure 1 is a perspective view of the invention; Fig.

2 is a perspective view of the two duplicate connector heads in coupled relation; Figs. 3 and 4 are face views of said heads, separated; Fig. 5 is a view principally in side elevation of one of the connector heads, some parts bein shown in section; Fig. 6 is a longitudina central section, taken on the irregular line as 00 of Fig. 2, on an enlarged scale; Fig. 7 is a face view of one of the terminal blocks, with its cover removed; Fig. 8 is a detail.view,'principally in section, taken approximately on the line a m of Fig. 1, on an enlarged scale, some parts being shown in different positions by means of dotted lines; Fig. 9 is' a detail view, principally in section, of the so-called connectparts throughout the several,

a side elevation of the bushing for the hand piece of the connecting piece.

In the drawings are shown connectors for a three-wire system, and the three conductors are indicated by the numerals 1,2 and 3. The insulation is removed from the ends of said conductors, and the bare ends thereof are inserted in sockets formed in the ends of three L-shaped conducting bars 4:, 5 and 6, respectively. Binding screws 7 are provided for securing the conductors l, 2 and 3 to the conducting bars 4:, 5 and 6, respectively. These conducting bars are insulated, one from the other, at 6, and are mounted in a terminal block 8 in the form of a rectangular box, constructed from any suitable insulating material.

A bracket 9 is provided for supporting the terminal block 8, and is preferably secured to the frame of a car vestibule dooropening leading to a coupled car, not shown. Only one terminal block is shown in the drawings, but it is, of course, understood that there is one of these blocks at each end comprises three metal bars 11, of suitable conducting material, in parallel arrangement and laterally spaced apart by insulating strips 12. These bars 11 are mounted in a rectangular casing 13 of suitable insulating material having its two ends open, so as to expose both ends of the bars 11.

The bars 11 are electrically and flexibly connected, one to each of the conducting barst, 5 and 6, by short heavy flexible wires 1 1. The insulation on the ends of these wires is removed, and their bare ends are inserted in sockets formed in the opposite ends of the conducting bars 4, 5 and 6 from which the conductors 1, 2 and 3 are secured, and in sockets formed in the inner ends of the bars 11. The outer ends of the bars 11 are re duced on two sides, to afford heavy rigid fingers 15. I

Cooperating with each finger 15 is a relatively thin yielding finger 16, constructed of the same material as the bars 11. These fingers 16 are of the same width as the fingers 15 and rest upon and extend the full 1 and yieldingly clamping the interlocked length of the bars 11. By reference to'Fig. 6, it will be noted that the space between cooperating fingers 15 and 16 is materially wider than the space between the fingers 15 and the adjacent inner face of the casing 13. This spacing of the contact fingers 1516 of one of the heads 10 permits the contact fingers of the other of the heads 10 to be inserted therebetween.

Opposing screws 17 are provided for holding the bars 11, casing 13 and contact fingers 16 in assembled relation. These same screws act as binding screws for securing the wires 1a in the bars 11. As best shown in Fig. 6,

the outer edge portions of the casings 13 extend beyond the outer ends of the bars 11, and, when the two connector heads 10 are coupled together, their interlocking contact fingers are completely covered. Duplicate clamps, carried one on each of the connector heads 10, are provided for yieldingly and frictionally clamping the contact fingers 16,

which are interlocked with the fingers 15,

onto said fingers 15, and said fingers 15 onto each other. Each of these clamps comprises a rectangular metal loop or band 18, a knurled thumb screw 19, a flat metal bar 20 and a bowed leaf spring 21. The band 18 snugly fits around the outer end portion of the casing 13, and the screw 19 has threaded engagement therewith adjacent to the underlying contact fingers 16. The casing 13, underlying the thumb screw 19, is recessed at 22, to receive the bar 20. A flat plate of insulating material 23 is interposed between the bar 20 and the contact fingers 16. The ends of the bowed spring 21 rest directly upon the bar 20, and the inner end of the screw 19 impinges against the intermediate portion of said spring. Obviously, by adjusting the screw 19, a varying pressure may be placed on the fingers 16, the bar 20 distributing the pressure equally thereover. To prevent the thumb screw 19 from being turned too far, and therebyjamming the intermediate portion of the spring 21 onto the bar 20, the same is provided with a shoulder 21 arranged to engage the band 18. By providing each "bar 11 with two laterally spaced contact fingers, which interlock with a like number of fingers on the cooperating bar 11, three contact surfaces are obtained between each set of cooperating fingers, thereby givmg a very large area of contact surface. The ends of the contact fingers 15-16 are rounded, to assist in'the easy assembling of tongues 20*, which interlock with notches 13 formed in thecasing 13, to hold said bar interlocked with the casing 13. The spring loop system.

21 is interlocked with the bar 20 by slot and pin connections 21 By frictionall-y fingers 1516 together, a good contact there'between is obtained,.at the same time allowing the coupled heads 10 to be separated under undue strains, in case the cars are uncoupled, thereby avoiding any damage to the electrical connections. The coupled heads 10 are loosely supported, with freedom for swinging movement and a limited lateral movement, on'a rod 26 secured to a part of the car vestibule frame, not shown. For supporting the coupled heads 10 .on the rod26, said heads are provided with apair of duplicate hooks 27 integrally formed, one on each of the bands 18. When the heads 10 are in coupled relation, these hooks 27 interlock, onewith the other, and

form a loop which embraces the rod 26. In

heads te be lifted from the rodv26 before uncoupling the same. j

To prevent sharp bending of the wires 14, at a point where they leave the terminal block, the bracket 9 is provided with an upwardly projecting curved extension 28, around which said wires may bend. In the vicinity of each terminal block is rigidly se' cured a dummy head29, of suitable insulating material, having a pair offvertically spaced fingers 30. When the connector heads 10 are not in use, the same-may be secured in idle positions to these dummy heads 29, by clamping their fingers 15-16 onto the fingers 30 of said dummy heads.

present, in making a good electrical connection vbetween two of the'conducting bars of terminal blocks, in completing the return- To overcome this difiiculty,

loop 27, in order, to permit the coupled- Considerable difficulty is experienced, at

ice

I provide a contact piece 31 of novel construction, for making an electrical connection betweentwo of the conducting bars of a terminal block. IEach ofthese contact pieces 31 comprises an annular'disk having a plurality of converging inrturned spring fingers 32, of suitable conducting. material. These fingers 32 are mounted for movement into and out of a-concave seat33 formed in the longitudinal adjacent edges of the bars 4 and 5, for making and breaking an electrical connection therebetween. The contact piece 31 is'provided withanjaxial stem 84, insulated therefrom at 341 and. mounted for rotary movement in the socket 35 of a hand piece '36. A set screw 37,- having screw threaded engagement with the hand piece 36, works in an annular groove 38 formed in the free end of the stem:3 1. This set screw 37 prevents endwise movement of. the stem 34' in' the socket 355, but permits-free rotary movement with respect thereto. 'The socket end of the hand piece 36 works in a bushing, 39 mounted in an opening in the cover of the terminal block 8, and is secured against removal therefrom by an opposing flange 40, integrally formed on, said bushing, and a nut 41 having screw-threaded engagement with said bushing. To impart an endwise movement to the socket end of the hand piece 36, to thereby move the contact fingers 32 into and out of the seat 33, the same is provided with a pair of oppositely projecting radial pins 4C2, which work in a spiral groove a3 formed in the internal face of the bushing 39. The hand piece 36, outward of its socket 35, is bent laterally, and also acts as a pointer as well as a hand piece. The words In and Out are marked on the terminal block, to indicate the position of the contact fingers 32, with respect to the seat 33. When the hand piece 36 points toward the word In, as shown in Fig. 1, the operator will know that the electrical connection between the bars 4: and 5 is complete. WVhenthe hand piece is turned toward the word Out, he will know that the electrical connection is broken. For the successful operation ofthe loop system, all of the electrical connections between the several conducting bars 4 and 5 must be broken, except the one at the. end of the train. The movement imparted by the hand piece 36 to the contact piece 31 is not only suflicient to carry its contact fingers into the seat 33, but will place the same under suflicient tension to insure a good contact between the conducting bars 4 and 5.

The above described device, while comparatively simple, is thought to be highly efficient for the purpose had in view. By making the two heads 10 duplicates, it is impossible to connect up the wires 14, at the coupled ends of two cars, except in their proper relation to each other, and it does not make any difference whichends of the cars are coupled up, as all of the connector heads are alike.

That I claim is:

1. Electric circuit connections on two cars having duplicate coupling heads, each of said heads being provided with a plurality of pairs of laterally spaced, relatively yield- Copies of this patent may be obtained for ing and rigid fingers that are insulated, one from the other, and with which the corresponding fingers of the other of said heads engage, and a clamp on each of said heads for frictionally clamping said yielding fingers, of one of said heads, onto the rigid fingers of the other of said heads, each of said clampscomprising a thumb screw having threaded engagement with a relatively fixed support, a bar resting on said yieldconnections leading to the contacts of said coupling heads, a relatively fixed supporting rod, and means, including duplicate, co-

operating hooks affording a loop on said head, adapted to embrace said rod for supporting the coupling heads thereon with freedom for swinging and a limited lateral movement.

4:. A car, having an electric circuit, including a head, having a pair of laterallyspaced, relatively-yielding and rigid contact fingers, a clamp for forcing said yielding finger toward said rigid finger, a flexible electric connection'leading to the contact fingers of said head, in combination with a dummy head having a finger onto which said contact fingers are adapted to be frictionally secured by said clamp in an inoperative position.

In testimony whereof I affix my signature in presence of two witnesses.

WILLIAM PATRICK MULLIGAN.

Witnesses:

- EMILY MAY KING,

HARRY D; KiLGonE.

five cents each, by addressing the Commissioner of Patents, -Washington, I). C. 

